Abstract

The Effects of Glyphosate and Multrazine on the Abundance and Diversity of Soil Microarthropods at the University Park, University of Port-Harcourt, Nigeria

The effect of two herbicides, Glyphosate and Multrazine on
the abundance and diversity of soil microarthropods (Mites
and Collembolans) was assessed in a field experiment
conducted from August to December, 2011 at the University
of Port Harcourt, Nigeria. The herbicides were applied at
varying doses of low (1.4 ml/m2 active ingredient; a.i,
standard (2.8 ml/m2 a.i) and high (5.6 ml/m2 a.i) for
Glyphosate; and low (2.1 ml/m2 a.i), standard (4.2 ml/m2 a.i) and high (8.4 ml/m2 a.i) for Multrazine; and control was
included. The experiment was conducted in a split-plot
design with six replicates arranged in a Randomized
Complete Block Design. Moist soil samples were randomly
collected from treated and control plots at the depths of 0-5
cm, 5-10 cm, 10-15 cm, and 15-20 cm, with an 8.5 cm2 diameter bucket-type auger. A total of 1080 soil
microarthropods comprising of 931 mites and 149
Collembola were recorded. Oribatid mites were the
dominant group being present at each sampling period.
Total soil micro arthropods collected were 554 Oribatid
mites, 377 Mesostigmata and 149 Collembola. The highest
number of soil micro arthropods was recorded from the
control treatment although this was not significantly
different from the numbers recorded from low and standard
doses of Glyphosate. All the three levels of Multrazine treatments significantly reduced the population of micro
arthropods compared with all the three levels of
Glyphosate. Both herbicides completely eliminated
Collembola from the treated plots. In all the treatments,
fewer soil micro arthropods were recorded as soil depth
increased.